Identification of carbonylated proteins from monocytic cells under diabetes‐induced stress conditions

A cross-sectional study to correlate antioxidant enzymes, oxidative stress and inflammation with prevalence of hypertension

AIMS

Hypertension a multifactorial consequence of environmental factors, life style and genetics is the well-recognized risk factor contributing to coronary heart diseases. The antioxidant imbalance, excessive reactive oxygen species (ROS) leads to oxidative stress which is pivotal in progression of hypertension. The present study aims to understand the complex interaction between oxidative stress, inflammation and antioxidant system which is crucial to maintain cellular homeostasis which further can exaggerate hypertension pathophysiology.

MATERIALS AND METHODS

The metabolic profile of hypertensive and normotensive subjects from Malwa region, Punjab was compared by estimating lipid profile, cardiac, hepatic and renal markers. The oxidative stress markers (protein carbonyls and lipid peroxidation), inflammatory markers (Nitric oxide, Myeloperoxidase and advanced oxygen protein products), and antioxidant enzymes (Superoxide Dismutase, Catalase, and Total Antioxidant Capacity) were analyzed.

KEY FINDINGS

It is observed that the metabolic markers are altered in hypertensive subjects which further these subjects showed increased oxidative, inflammatory profile and compromised antioxidant status when compared with normotensive subjects. Co-relation analysis validated the involvement of inflammation and oxidative stress in impaired endothelial function and vital organ damage.

SIGNIFICANCE OF STUDY

These markers may act as early indicators of hypertension which usually do not show any physical symptoms, thus can be diagnosed and treated at the earliest. The current study suggests that disturbed homeostasis, a consequence of altered interaction between antioxidant system and inflammatory events raises the oxidative stress levels which eventually leads to hypertension and associated complications. These indicators can serve as early indicators of future chronic complications of hypertension.

Effects of edaravone on oxidative protein modification and activity of gelatinases after intracerebral hemorrhage in rats with nicotinamide-streptozotocin induced diabetes

Stroke, especially hemorrhagic form, is one of the most serious comorbidity disease of diabetes mellitus, often associated with high mortality, particularly in type 2 DM (T2DM). Therefore, it is relevant the search for drugs with a metabolically justified protective effect. Edaravone (Eda) is widely used for treating ischemic stroke but its biochemical effects in intracerebral hemorrhage (ICH) associated with T2DM is not still confirmed. The aim of the study was to assess the impact of Eda on the markers of oxidative modification of proteins (OMP), such as advanced oxidation protein products (AOPP), neutral and basic carbonyls (PC370 and PC430), advanced glycation end products (AGE) and ischemia modified albumin (IMA) as well as on the activity of matrix metalloproteinases MMP2/MMP9 (gelatinases) in rats with experimental T2DM after collagenase-induced ICH. Metformin was used as a comparative drug. The data obtained indicate that ICH in diabetic rats is accompanied by an increase in AOPP, PC370, AGE, and mature forms of both gelatinases. On the contrary, IMA and proMMP9 were below normal level after ICH. Both studied drugs decreased the OMP markers to the levels of intact rats or lower, and Eda show a more potent effect. Besides, Eda significantly decreased the activity of MMP9 and changed progelatinases activity. We conclude that Eda has a perspective to be useful in the treatment of comorbid brain hemorrhage in T2DM due to inhibiting of oxidative stress and modulation of gelatinases activity.

Changes in biomarkers of endothelial function in the blood after intracerebral hemorrhage in rats with type 2 diabetes mellitus

Clinical evidence suggests that type 2 diabetes mellitus can increase the risk of intracerebral hemorrhage and provocation of neurodegeneration. This study was aimed at evaluating biomarkers of glycemic control, lipid profile, oxidative modification of proteins, as well as the functional state of endothelium in Wistar rats with type 2 diabetes mellitus complicated by intracerebral hemorrhage. Experimental type 2 diabetes mellitus was induced by intraperitoneal injection of streptozotocin (65 mg/kg) and nicotinamide (230 mg/kg). The intracerebral hemorrhage was induced by microinjection of sterile saline containing 0.2 IU bacterial collagenase into the striatum. Assessed biomarkers included the area under glycemic curve, glycated hemoglobin, total cholesterol, triglyceride, high-density lipoprotein, advanced glycation end products, markers of oxidative modification of proteins – aldehyde- and ketonephenylhydrazones, and markers of endothelial dysfunction – homocysteine, endothelin-1, von Willebrand factor and asymmetric dimethylarginine in blood serum. Both rats with type 2 diabetes mellitus and rats with intracerebral hemorrhage and diabetes had a significant elevated glycemic control as compared to intact animals. But combined pathology was additionally characterized by an impairment of lipid profile (increased triglyceride level and decreased as total cholesterol and high-density lipoprotein) resulting in a rise in the atherogenic index of plasma. A significant increase in the content of the markers of oxidative modification of proteins was observed in both experimental groups. But the rats with intracerebral hemorrhage and diabetes only had higher levels of advanced glycation end products in comparison with intact animals. The highest levels of endothelin-1, as a biomarker of endothelial dysfunction, were observed in animals with intracerebral hemorrhage and diabetes. Homocysteine and von Willebrand factor were elevated in rats with type 2 diabetes mellitus, while acute intracerebral hemorrhage did not potentiate the further growth in its levels. Such effect was not accompanied by a marked increase of asymmetric dimethylarginine level in blood serum, although there was a clear trend. In conclusion, the development of intracerebral hemorrhage in rats with type 2 diabetes mellitus can intensify the manifestations of oxidative stress, worsen lipid profile, and aggravate endothelial dysfunction. In this case, the pathological process may have the character of a “vicious circle”.

Caffeine prevents oxalate-induced epithelial-mesenchymal transition of renal tubular cells by its anti-oxidative property through activation of Nrf2 signaling and suppression of Snail1 transcription factor

Caffeine is an active ingredient found in coffee and energy beverages. Its hepatoprotective effects against liver fibrosis are well-documented. Nonetheless, its renoprotective effects against renal fibrogenesis and epithelial-mesenchymal transition (EMT) processes remain unclear and under-investigated. In this study, the protective effects of caffeine against oxalate-induced EMT in renal tubular cells were evaluated by various assays to measure expression levels of epithelial and mesenchymal markers, cell migrating activity, level of oxidized proteins, and expression of Nrf2 and Snail1. Oxalate at sublethal dose significantly suppressed cell proliferation but increased cell elongation, spindle index and migration. Oxalate also decreased expression of epithelial markers (zonula occludens-1 (ZO-1) and E-cadherin) but increased expression of mesenchymal markers (fibronectin, vimentin and α-smooth muscle actin (α-SMA)). All of these EMT-inducing effects of oxalate could be prevented by pretreatment with caffeine. While oxalate increased oxidized proteins and Snail1 levels, it decreased Nrf2 expression. Caffeine could preserve all these molecules to their basal (control) levels. Finally, silencing of Nrf2 expression by small interfering RNA (siRNA) could abolish such protective effects of caffeine on oxalate-induced EMT. Our data indicate that the renoprotective effects of caffeine against oxalate-induced EMT is mediated, at least in part, by its anti-oxidative property through activation of Nrf2 signaling and suppression of Snail1 transcription factor.